long sleeps to avoid timeouts

Author: GaelVaroquaux

Makefile

@@ -10,7 +10,7 @@ html:
 	rm -rf modeling_short.ipynb modeling_short.py
 	# Now build the app
 	export DEBUG=False && python3 app.py &
-	sleep 30
+	sleep 60
 	wget -r http://127.0.0.1:8050/ 
 	wget -r http://127.0.0.1:8050/_dash-layout 
 	wget -r http://127.0.0.1:8050/_dash-dependencies